Rotary tool



Nov. 4 1924. 1,514,415

0. G. ARNOT ROTARY TOOL Filed Oct. 21., i922 l/v VENTOF? 0 WEN G. A RNOTAQ MIAWMQ Arrvsz- Patented Nov. 4, 1924.

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ROTARY TOOL.

Application filed October 231, 1922.

California, have invented new and useful Improvements in Rotary Tools,of which the following is a specification.

This invention relates to drill bits and more particularly to drill bitsfor deep well rotary tool rigs.

It is an object of the invention to provide a multiple bladed tool.Another object is to provide a multiple bladed tool having a singlesplit shank.

Another object is to provide a rotary bit having great length of life soas to be operable for a much longer period before re moval from the wellhole for sharpening. Another object is to provide a fish tail bit withmore than two cutting points and all of which are substantiallysymmetrically arranged with respect to the center of rotation of the bitand to provide a bit which will not readily clog or choke up in the wellhole. It is also an object to provide a multiple bladed bit with morethan two cutting points so as to secure an effective cutting action torun the hole true and straight and to overcome the tendency, as found ina single blade fish tail bit, to shift from a true line of out.

Another object is to provide a fish tail bit with the peculiararrangement of water courses, one of each being on the outside faces ofthe bit and one centrally of the bit.

Other objects and advantages will be made manifest in the followingspecification of an embodiment of the invention illustrated in theaccompanying drawings, wherein Figure l is a side elevation of theimproved bit looking toward edges of its multiple blades.

Fig. 2 is a bottom end plan of the bit.

Fig. 3 is a side elevation of the inside face of one of the bits.

The improved fish tail bit of my invention consists of a sectionalconstruction in which a plurality of blade-like sections 2 are utilized,each of these blades having at its upper end a shank or head portion 3.Each shank portion 3 is provided with a meeting or abutment face 4 sothat the sectional parts of the bit may be assembled with the respectiveshank portions 3 in, abutment at their faces 4. In the present case,each shank Serial No. 595,944.

section 3 is substantially semi-circular and its abutment face isdiametrical, and two of the sections are adapted to be placed face toface and to thus position the blades 2--2 in transverse opposition. Thesections of the bit may be rigidly secured together to act as a unitarycutter, and means are here shown comprising exterior threads 5 on thetapered shank portions 3, which threads are adapted to be engaged by acomplementary drill socket or sleeve, not shown, and whereby the bit isrotated.

For fastening the pieces together until secured in a drill collar orsleeve, they may be joined by transverse bolts or rivets 6. The upperends of the shanks 3 are shown as turned down to form stem sections 7,and these sections when set face to face form a cylindrical projectionwhich is externally screw-threaded at 8 to receive a fastening collar 9which is shown of less diameter than the upper end of the threaded shankportion.

The lower ends of the blades 2, which may be tapered downwardly, areshown as provided with usual fish tail cutting points 2 The cuttingpoints, as clearly shown in Fig. 2, are all arranged in symmetricalorder on diametrically opposite sides of the axis of the bit, and bythis arrangement of four cutting points, the cutting action of the bitwill be maintained more nearly to a straight line path during therotation of the bit than is possible where fish tail bits of only twocutting points are driven.

Another feature of the invention is the provision of water coursesthrough the shank of the bit. Such courses are here represented aslongitudinal apertures 10, 11 and 12. The aperture 10 is produced byforming grooves axially in the meeting faces 4 of the shank section 3,so that when these sections are placed face to face the groove will forman axial water course 10 which will discharge downwardly between thespaced blades 2-2 of the bit. The water courses 11 and 12 may be formedas drill holes run from the upper end of the shank sections 33 to thelower ends of the shanks where the water courses discharge outside ofthe outer faces of the blades 22.

Further embodiments, modifications and changes may be resorted to withinthe spirit of the invention as here claimed.

What is claimed is:

1. A rotary bit comprising a plurality of blades each having oppositelytwisted cutting ends, the blades having portions forming a shank body toreceive a driving means and water courses eXtending through theassembled shank body and discharging outside of the blades and betweenthe blades.

2. A rotary drilling tool comprising blades having opposite, parallelportions and each blade being provided with a fish-tail cutting end, thecorners of the fish-tail ends all be-v ing twisted -forward in thedirection of the rotation of the tool.

3. A rotary bitcoinprising two blades,

each blade carrying a portion forming half a shank body, the two halfshank bodies being secured together and externally screwthreaded to forma pin for connection to a drill stem, the lower ends of the blades beingof fish tail form, the cutting corners being twisted in the direction ofrotation.

a. A rotarybit comprising two blades, the lower ends of each blade beingof fish tail form, and the cuttin corners being twisted in the directionof rotation.

In testimony whereof I have signed my name to this specification; I h

OW EN G; ARNOT.

